The Duke, Duchess and Prince attended the marathon in aid of Heads Together, their mental health charity which saw thousands of runners don a bright blue charity headbands to raise awareness.

Among the runners was the Telegraph's Bryony Gordon, who raised more than £35,000 and surpassed her own expectations by finishing in five hours 53 minutes.

The stars of the show, the Heads Together runners, celebrated the "extraordinary" reception they had received by cheering members of the public, hailing the royals for all they have done this week to raise awareness.

The Duke of Cambridge hugs a runner as he hands out water Credit:
Chris Jackson/PA Wire

Prince Harry was nicknamed the "royal hugger-in-chief" at the start line, after he, his brother and his sister-in-law offered a few last-minute words of encouragement to runners including military veterans, a family who lost their father to suicide, and a woman dressed as a strawberry.

The three royals were tasked with sounding the klaxon to officially start the race, and set the tone for the day after being photographed larking about with their air horns.

At their next appearance, in Greenwich, the Duke and Duchess and Prince Harry were mobbed by runners when they joined Heads Together supporters at a cheering point on the marathon route.

Evan Williams, his brother Ian and friend Graham O’Loughlin broke the world record for the fastest marathon in a three person costume, wrapping themselves in an enormous blue headband to finish in 3 hours 13.

Among the everyday heroes cheered on by spectators was Matthew Rees, 29, who sacrificed his own race time to help a fellow runner seen staggering along the final stretch.

To raucous cheers, the Swansea-based runner put his the stranger's arm around his neck and hauled him to the end of the 26.2-mile course.

Matthew Rees helped another runner over the lineCredit:
ADRIAN DENNIS/AFP

Mr Rees said afterwards: "I saw him try to stand up again and his legs just went down again, and I thought 'this is more important, getting him across the line is more important than shaving a few seconds off my time'."

Britain's leading mental campaigners said the Heads Together event marked a "pivotal moment" in the treatment of the illness.

Paul Farmer, chief executive of Mind, said the runners and Royals had brought "unprecedented attention" to an overlooked cause, saying people with mental health problems "cannot be overlooked any more".

The Telegraph's Bryony Gordon with her medalCredit:
Paul Grover

Bryony Gordon, the Telegraph columnist who ran the marathon for Heads Together yesterday, said the candid disclosures of Prince Harry and Duke and Duchess of Cambridge this week have opened the floodgates to "smash the stigma".

A Kensington Palace spokesman said last night: "The Duke and Duchess and Prince Harry are thrilled that so many runners have chosen to wear Team Heads Together headbands.

"Regardless of the great causes they are running for, thousands of people have put on a headband to make this the Mental Health Marathon."

Bryony Gordon said of the marathon: "It was absolutely incredible. It's been the most amazing week.

"The finish line is just the beginning. I genuinely think the floodgates have opened this week. It's really special and things have really changed.

"The more we smash the stigma, the more the powers-that-be have to increase funding and give mental health parity with physical health.

"For me, the thing now is to get all the party leaders to pledge to ring fence mental health funding and make it a huge commitment in their manifesto."

Bryony Gordon crosses the finish lineCredit:
Paul Grover

Paul Farmer, from Mind, said: “Yesterday’s London Marathon, and the Heads Together campaign, marked a pivotal moment for mental health.

"In fact, the whole of last week brought unprecedented attention to mental health, but there’s still so much more to do.

"Mental health has for too long been overlooked, underfunded and in the shadows.

“As more people join the ranks of those willing to speak out about mental health, the demand for change will be unstoppable."